A composition for separating out volatile pollutants from gases and exhaust gases consists of calcium hydroxide and water-soluble salts of sulfur-containing compounds, e.g., mercaptans, sulfides, polysulfides, polythionates and thiosulfates, or elementary sulfur which are used in combination with surface-active substances.
Possible ways to produce the composition include adding the sulfur-containing compounds to the quicklime during slaking, to the slaking water, or, subsequent to slaking, to calcium hydroxide.
The compositions are used for removing the volatile heavy metals, particularly mercury, arsenic, cadmium, thallium, antimony and lead, at temperatures ranging from 20.degree. to 400.degree. C. For this purpose, the composition is blown as powder into the exhaust gas stream, and the resultant products are separated out at fabric filters. Upon addition of surface-active substances, volatile organic pollutants are removed simultaneously with the aforementioned inorganic pollutants.